// Copyright (C) Kumo inc. and its affiliates.
// Author: Jeff.li lijippy@163.com
// All rights reserved.
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.
//
#pragma once

#include <pollux/common/base/status.h>
#include <pollux/common/memory/byte_stream.h>

namespace kumo::pollux::serializer::presto::detail {
    struct PrestoHeader {
        int32_t numRows;
        int8_t pageCodecMarker;
        int32_t uncompressedSize;
        int32_t compressedSize;
        int64_t checksum;

        static Expected<PrestoHeader> read(ByteInputStream *source);

        static std::optional<PrestoHeader> read(std::string_view *source);

        template<typename T>
        static T readInt(std::string_view *source) {
            assert(source->size() >= sizeof(T));
            auto value = melon::loadUnaligned<T>(source->data());
            source->remove_prefix(sizeof(T));
            return value;
        }
    };
} // namespace kumo::pollux::serializer::presto::detail
